Surface Effects of Soft Drinks to Composites

Objectives: to evaluate the effect of carbonated soft drinks over the surface of composite resins.

Methods: Thirty composite disks, 2mm thick and 10 mm in diameter were fabricated of each of four composite resins: Filtek Supreme XT (3M ESPE), Filtek LS (3M ESPE), Grandio (VOCO GmbH) and TPH3 (Dentsply). Specimens were divided into six groups (n=5) to be soaked in four carbonated soft drinks and one in water as control. The remaining group was used for SEM observations. Soft drinks used were Coca-Cola regular¨, Coca Cola Zero¨, Squirt¨ and Gasified Grape Tropical¨. Specimens were immersed in the soft during for 30 minutes per day, then removed from the drink and placed in water. Vickers hardness (VHN) was recorded at baseline, and after 15, 30 and 60 days of treatment. Data was recorded in VHN and analyzed using a repeated measurement ANOVA calculated at 0.05 significance level. Tukey-Kramer test for differences among groups was also calculated at 0.05.

Results: VHN at baseline and after 60 days are shown intable. Hardness for all composites evaluated decreased after being 60 days. All soft drinks used in this study produced the same decreasing effect on all composites. SEM observation showed an increment in the number and size of defects on the surface after the 60 days treatment.

	Coke		Coke Zero		Squirt		Grape			water
	BL	60d	BL	60d	BL	60d	BL	60d	BL		60d
Z350	75	71	76	73	70	67	77	73	75		76
P90	52	45	55	50	51	49	52	46	53		49
TPH3	60	56	57	55	62	61	64	57	61		60
Grandio	91	83	90	89	97	90	89	85	88		84

Conclusion: As little as 30 minutes of contact time per day, carbonated soft drinks produce a negative effect on the surface of composite resins evaluated.